Renewal of the filaments in metal filament electric lamps



S. COXON AND W; A. WILLIAMS.-

RENEWALOF THE FILA MENTS 1N METAL FILAMENT ELECTRIC LAMPS."

APPLICATION FILED SEPT. 2, 1920 a 1,%22,7%7 YatentedJu1y 111 M22;

s. COXON ANDW. A. WILLIAMS.

RENEWAL OF THE FILAMENTS IN METAL FILAMENT ELECTRIC LAMPS.

APPLICATION FILED SEPT-2,1920.

1,422,747 Patented July II, 1922;

2 SHEETSSHEET 2.

" ygww "i'rsos'rnrss PATET orrlc. v

SYDNEY cox on', oI LIvEnroon ND WILLIAM ALBEnrwILLIAms, or

-- I'meLanD, ASSIGNOBS 'ro THE ALADDIN RENEW EY, ELECTRIC LAME coarone'rrortm s n, or Lennon, ENGLAND, A BRITISH coaronArron.

* wAL or Erna FILAMENTS IN III TAL FILAMENT ELEcmIc LAMPS.

Specification of Letters Patent.

Patented Jelly 11, 11922.

, Application filed September 2, 1920. Serial llo. 407,755.

To all may concern I A ire, England, have invented certain new and useful Improvements in the Renewal of the Filaments in Metal Filament Electric Lamps, of which the following is a specification.

I ,This invention relates to improvements n the renewal or replacing of the filaments of metal filament electric lamps. Such filaments have previously been renewed by first removing the old spent filament by we of anaperture formed in the tip ofthe globe, a temporary lower scafl'old bemg then fitted beneath the permanent lower scaffold and the new filament wound on to the upper permanent scafiold, and the lower temporary scaffold, after which the new filament was transferred from the temporary scafiold to the permanent lower scaffold. In some arrange ments also a special fitting was used for connecting the ends of the new filament to the leading in wires. 7

The present invention provides an economical process of effecting the renewal of the metal filament, whereby the temporary scaffold is dispensed with.

The process of the present inventlon is characterized by the fact that the new filament is wound directly round the upper permanent scaffold wires and the roots of the lower permanent scafi'old wires, whereby owing to the considerable rigidity ofiered by such frail wires at the roots the filament may be mounted directly thereon without the aid of a temporary scafi'old. Such a process is applicable when using a straight filament to the renewal of all lamps in which the lower scafiold wires, at or near their base, are sufiiciently stifi relatively to the stifiness of the filament to enable the requisite tension to be placed upon the filament to straighten each bight between the upper hooks and the lower scafi'old wires in the process of winding.

Preferably, the lower scaffold wires are first bent downwardly close to the roots, the new filament is wound on them and set, and subsequently the depending loops of the filament are moved from the roots to the outer ends of the lower scafiold wires.

'place by means of nozzle through which the threaded. The whole of The setting may vacuum by flash filament.

The invention also relates to the-manner of connecting the filament to the leading-in wires. According to the invention of an open hooked end is formed on a leading-in wire; the filament is wound several times be effected in a partial mg a current through the round the hook and to facilitate trimming oif t he end of the filament close to the leadmg m wlres a bight or stretch of filament is left extending from the wound hook across to the other leading-in'wire. This bight may be readily cut.- .The wound hook is y preferably closed before cutting.

The filament may be readily wound in an of a length of glass tubing having a pointed filament is the operations above described are performed within the lamp bulb, access bemg gained to the interior thereof by a hole in the bulb. This hole, instead of being central with they tip, as heretofore customary, is preferably disposed substantially eccentric to the axis of the glass stem of the scafiold wires. The implements used in rewiring may therefore be passed up into the bulb clear of the usualwire bead on the glass stem.

The invention is illustrated in the panying drawings, in which: "Figure 1 is a view of a lamp showing the arrangement of the metal filament when renewing; V

Figure 2 shows the manner of making the first connection ,to the leading-in wires;

Figure 3 is analogous to Figure 2 showing the manner of making the final connection of the filament to the leading-in wires; 1

Figure 4 is an inverted plan of Figure 1 showing the eccentric disposition of the aperture formed near the tip of the bulb;

Figure 5 is a view of an implement suitable for forming the hooked ends on the leading-in wires:

Figure 6 shows an implementfor closing the hook on the leading-in wires; and

Figure 7 illustrates an implement for cutting the filament.

In carrying out the invention, an aperture 1 is formed in the tip of the bulb 2 and the old filament removed fromv the upper and lower permanent scafi'old wires, 3, t of the implement consisting the leading-in wire 6 round which the filalamp in any suitable manner as by washing out. Open hooked ends 5 are then formed on the ends of the leading-in wires 6, 6, and the new filament wound on in the following manner. I The filament wire is carried over the hooked end of one leading-in wire 6, Figure 2, and; wound several turns, preferably,- round the hooked end of the other leading-in wire 6, leaving a straight length of filament a from one leadin -in wire to the other. The open hooked en of ment has been wound is then closed up tightly to make electrical connection therewith. A cutting device is then passed up through the aperture 1 of the lamp and the filament out between the two leading-in wires 6, 6, the loose tail piece 5 of filament being withdrawn, Either previously or at this stage, the lower permanent scaffold wires 4 are bent downwards near the root where they are embedded in the glass stem as shown in the full lines Figure 1. One'end of the new filament 0 being now secured to the end of the leading-in wire 6, the filament is carried down and passed close round the root of the first lower scaffold wire 4 and up round the outer hook on the first upper scaffold wire 3, down and under the next lower scaffold wire near its root, and over the next upper scaffold wire hook, and so on round the outer hooked ends of the upper scaffold wire and theinner roots of the lower scaffold wires until the looped formation is completely carried round the upper and lower scaffold wires, the end of the filament being then wound, preferably, several turns round the open hooked end of the remaining leading-in wire 6, Figure 3, and then carried across and over the other leading-in wire 6 to leave another straight length d. The

open hooked end on the wire 6 is then closed firmly, securing the end of the filament and making electrical connection therewith. The cutting device is then inserted and the filament cut across -'this straight length. After the filament has been wound in this way a partial vacuum is set up in the lamp and a current flashed through the filament. This operation sets the filament. The lower scaffold wires 4 either at this stage or before flashing, are bent upward to their original position shown in dotted lines 4* Figure 1 and the lower tips of the filament loops are passed radially outward from the roots' along the lower scaffold wires 4 unon the leading-in wires for the new filament,

other material and-having a pointe nozzle 16 is threaded on the new filament 0. The hole through which the filament issues from the nozzle is preferably situated eccentrically. In the drawing the tube16 is shown larger than the preferred size'which is about three to five millimeters external diameter. During the operation of winding, this tube serves as a manipulating handle, by means of which the filament may be quite easily passed'up throughthe aperture 1 formed in- -the bulb and worked round the leading-in wires 6, 6, and up and down round the scaf-' fold wires 3, 4 toform the loops. During this operation the scafiold wires 4 can be pushed to one side somewhat if necessary, as they have to be adjustedin position sub sequently. By winding the filament round the roots of the lower scaffold wires, advantage is taken of the considerable rigidity offered by such scaffold wires atthese points,

it being impossible in most cases to wind the filament round the outer tips of the lower scaffold owing to the resilience of the filament before flashing and the weak nature of the wires i and, further, as the filament afterwards shrinks, allowance should be made for the shorter length of the loops which the wire will then assume, andby winding the wire obli uely from the outer tips of the upper sca old to the inner roots of the lower scaffold the diagonal length thus imparted to the loops approximately corresponds to the increased length which is required in the loops to allow for their subsequent contraction when flashed, and when engaging the outer ti s of the lower scafi'old.

In or er to form hooked ends on the upper leading-in wires, an instrument Figure 5 is provided consisting of a tubular stem 17 in which is slidably mounted an inner rod 18 having a manipulating button or ring 19 at the outer end, the other ends of the tubular stem and the inner rod being formed as a knife edge 20 and double jaw 21 so that when engaged over the leading-in wires 6, 6 and the jaws closed, a hook end is formed. A modification of this instrument with the jaws reversed to form a downward hook is necessary for putting hooked ends on any of the lower scaffold wires 4 which may have become damaged.

An instrument suitable for closing the open hooked ends of the leading-in wires in order to nip the filament is shown in Figure 6 where the pivoted jaws 7 and 8 are carried at the end of a long stem 10 so that the instrument may be inserted readily through mama? the aperture-1. A corresponding instrument is shown in Figure 7 suitable for cutting the bights a, d of the filaments, the shears 11 being actuated at the end of a long stem 12 from the handles 13.

y forming the aperture 1 as shown slightly out of centre towards the side of the lamp opposite the leading-in wires, a greater facility is obtained in passing up the instruments to treat the ends of the leading-in wires 6, 6, this eccentricity of the aperture enabling the instrument to clear the lower bead 14: on the glass stem 15.

hat we claim as our invention and desire to secure by Letters Patent is 1. The process of renewing the metallic filament upon the permanent supports within an electric incandescent lamp without removing them from the bulb, comprising making an opening in the bulb, winding the new filament directly round the upper permanent scafiold wires and the roots of the lower permanent frail scaffold wires, setting the filament, then moving the depending loops of the filament from the roots .to the outer ends of the lower scafi'old wires.

2. The processof renewing the metallic filament upon the permanent supports within an electric incandescent lamp without removing them from the' bulb, comprising making an opening.in the bulb, bending down the lower permanent scaffold wires.

near the roots, winding the new filament directly round the upper permanent scafi'old wires and the roots of the lower frail scafi'old wires, setting the filament,

then bending back such frail wires to their original position and moving the depending loops of the filament from the roots to the outer ends of the lower scaffold wires.

3. The process filament upon the in an electric incandescent lamp without removing them from the bulb, comprising making an opening in the bulb, forming an open hooked end on one leading-in wire,

permanent of renewing the metallic permanent supports withwinding the filament several turns round the hook and leaving a stretch or bight of the filament from the wound hook to the other leading-in wire, closing the hook and cutting such bight, winding the new filament directly round the upper permanent scaffold wires and the roots of the lower permanent frail scaffold wires, setting the filament, then moving the depending loops of the filament from the roots'to the outer ends of the lower scafi'old wires.

4. The process of renewing the metallic filament upon the permanent supports within an electric incandescent lamp without removing them from the bulb, by forming an aperture in the base of the lamp bulb disposed substantially eccentric to the axis of the glass stem to enable the implement used in rewiring to-be passed into the bulb clear of the usual lower bead on the glass stem, windingthe new filament directly round the upper permanent scafi'old wires and the roots of the lower permanent frail scaffold wires, setting the filament, then moving the depending loops of the filament from the roots to the outer ends of the lower scaffold wires.

5. The process of renewing the metallic filament upon the permanent supports withmoving them from the bulb, comprising making an opening in the bulb, placing the in an electric incandescent lamp without renew filament on the upper permanent scaffold wires and round the lower permanent frail scaffold wires at points removed from their outer ends, setting the filament and then moving the depending loops of the filament to the outerends of the lower scafi'old wires. 7 In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

SYDNEY COXON. WILLIAM. ALBERT WILLIA MS. Witnesses:

A. J. DAVIES, E. Hnemnorrnm. 

